tbuckley/cabot-search huggingface dataset:
Abstract P1002: Impact Of Maternal Diabetes-associated Oxidative Stress On The Developing Endocardium
Authors: Talita Z Choudhury, Sarah Greskovich, Holly Girard, Emily Cameron, Vidu Garg
Journal: Circulation Research (2023)

Congenital heart defects (CHD) affect 1% of all live births and are the leading cause of birth defect-related mortality. The etiology of CHD is multifactorial as genomic variation and environmental factors act as contributors. Among the environmental teratogens, maternal pre-gestational diabetes mellitus and its concurrent maternal hyperglycemia (matHG) is associated with a ~5-fold increased risk of CHD. Oxidative stress (Ox-Stress) due to generation of excess reactive oxygen species is observed in embryonic hearts exposed to matHG in animal models, but its teratogenic effect on cardiac development is not understood. Additionally, we observed murine embryonic hearts exposed to matHG have reduced expression of Notch1, which is highly expressed in endocardial cells (EC) and reported a gene-environment interaction between matHG and Notch1 haploinsufficiency that results in CHD in mice. We hypothesize that matHG-induced Ox-Stress leads to the downregulation of endocardial Notch signaling and aberrant EC function leading to CHD. To investigate the effects of matHG-induced Ox-Stress on endocardial Notch signaling, we examined mouse embryos exposed to matHG with conditional deletion of Notch1 in EC. We used lineage tracing to detect differences in EC-derived structures in hyperglycemia and normoglycemia-exposed embryonic hearts. Finally, we asked whether modulating intracellular levels of Ox-Stress can rescue the CHD phenotypes observed with matHG exposure by generating mouse embryos with overexpression of the antioxidant gene, SOD1 . Results show conditional deletion of endocardial Notch1 in embryos exposed to matHG leads to highly penetrant CHD. We found increased Ox-Stress and reduced number of EC-derived mesenchymal cells in endocardial cushions of mouse hearts exposed to matHG. Finally, embryos with SOD1 overexpression have reduced Ox-Stress and decreased incidence of CHD compared to non-SOD1 overexpressing littermates. This works shows that matHG-induced Ox-Stress may be associated with aberrant EC and EC-derived cell function via disruption of Notch signaling. Mitigating Ox-Stress during cardiac development may lead to rescue of Notch signaling and EC function to reduce CHD incidence from matHG exposure.
Abstract P3118: Gender Differences In The Efficacy Of A Mobile-based Self-management Program For Patients With Heart Failure
Authors: Jeong-Ah Ahn
Journal: Circulation Research (2023)

Background: This study was to develop a mobile application (App) program, presenting educational materials and giving interactive feed-backs on self-management for heart failure patients and to evaluate the gender differences in the efficacy of the program. Methods: We developed a mobile App program for heart failure patients’ self-management, which included comprehensive educational materials and daily record logs for the patients. Also, it took into account the mobile use characteristics and convenience of aged heart failure patients, as well as active and instant interactions and feedback via group chat among the patients and healthcare providers. Regarding the experimental study, we employed a randomized controlled trial to evaluate the effects of the program in 66 heart failure patients. The intervention group was guided to use the mobile App program in their daily life at home for 3 months. Results: Male patients in the experimental group exhibited significantly decreased waist circumference and improved NYHA functional class than the control group after 3 months. As for female patients in the experimental group, they showed significantly improved NYHA functional class, depressive symptoms, and quality of life than the control group after 3 months. Conclusion: This mobile App program showed effective improvements in heart failure patients' symptom classes for both men and women. Also, it showed that women had overall higher positive outcomes in psychosocial aspects, such as depressive symptoms and quality of life than men. Future study is needed to develop self-management programs considering gender differences and also to understand their effectiveness according to gender.
Abstract P3040: Development Of A Protein Synthesis Network At The Sarcoplasmic Reticulum In Adult Cardiomyocytes
Authors: Christoph Hofmann, Sören Brandenburg, Dennis Uhlenkamp, Bianca Meyer, Clara Sandmann, Nicole Herzog, Julia Groß, Viviana Sramek, Marc Renz, Hugo A Katus, Stephan E Lehnart, Mirko Völkers, Shirin Doroudgar
Journal: Circulation Research (2023)

Introduction: The endoplasmic reticulum (ER) is the site of synthesis and folding of membrane and secretory proteins. In striated muscle cells, a specialized membrane system known as the sarcoplasmic reticulum (SR) sequesters Ca 2+ and carries key functions in excitation-contraction coupling. Textbooks often define the SR as the ER of muscle, but surprisingly, the biochemical and physiological relationship between the ER and SR and even whether they are distinct membrane networks or refer to the same structure remain unknown. Methods: To characterize the relationship between the ER and SR, we applied biochemical and imaging techniques, including immunofluorescence and election microscopy, fluorescence in situ hybridization, and STimulated Emission Depletion (STED) microscopy to ventricular myocytes, which allowed us to follow the differentiation of these membrane compartments in developing cardiomyocytes. Results: Using localization and expression levels of SERCA2, RyR2, KDEL and different markers of ribosomes, mRNA, and the secretory pathway, we found that the membrane compartment that exists in the early postnatal stage, resembles mostly the ER, and this membrane system decreases in postnatal development. The SR is the main membrane network that exists in the adult cardiomyocytes, replacing the ER, in all but a small perinuclear region. Both sites which appear to be interconnected, perform specialized tasks, with protein secretion through the classical ER-Golgi secretory pathway originating mainly from the perinuclear ER and Ca 2+ -dependent excitation-contraction coupling originating exclusively from the SR. Other functions, such as Ca 2+ intake or posttranslational protein processing occur in both compartments. Importantly, we show that in adult cardiomyocytes ribosomes are not only attached to the ER but also to the SR, where they actively perform mRNA translation and are major sites of protein synthesis. Conclusion: The ER and SR are two distinct coexisting membrane networks in cardiomyocytes that undergo molecular differentiation and structural organization during cardiac muscle development. Significant amounts of protein synthesis occur in adult cardiomyocytes at the SR and may serve localized mRNA translation near the sarcomere.
Abstract P2107: Latent Transforming Growth Factor Binding Protein - 2 Deficiency Improves Cardiac Function Post-Myocardial Infarction
Authors: Fahad Ehsan, Michael Dewar, Tao Wang, Aliya Izumi, YU-QING ZHOU, Hangjun Zhang, Scott P Heximer
Journal: Circulation Research (2023)

Cardiac fibrosis and myocardial stiffening are key factors contributing to deteriorating cardiac function during heart failure, especially after myocardial infarction (MI). In the myocardium, cardiac fibroblasts (CFs) are the main cell type driving excess extracellular matrix (ECM) protein deposition, leading to pathological remodelling of the heart. Latent Transforming Growth Factor Binding Protein 2 (LTBP2) is one of the ECM proteins released as part of the fibrotic response and is significantly upregulated in all types of heart failure. Although LTBP2 belongs to a family of proteins that regulate the release of Transforming Growth Factor - β; (TGF-β;) in the ECM, it doesn’t interact with TGF-β;. Nonetheless, LTBP2 is shown to play a role in the progression of fibrosis following heart failure by contributing to CFs activation. Therefore, we hypothesized that in the absence of LTBP2, the heart would have improved cardiac function following MI. We used LTBP2 knockout (KO) C57BL/6 mice and modelled MI by ligating the left anterior descending artery. Echocardiography was performed to analyze the cardiac function in KO and wild-type (WT) infarcted hearts at 7 and 28 days post-MI. KO mice showed significantly better ejection fractions (KO = 24.1±4.9% vs. WT = 9.2±1.4%, p-value &lt; 0.01) and fractional shortening 28 days post-MI compared to WT mice. In conclusion, our findings show that LTBP2 contributes to the deteriorating cardiac function following MI suggesting that targeting LTBP2 may have therapeutic potential. As LTBP2 is known to be a part of the fibrotic response, future studies will investigate the fibrotic profile of WT and KO infarcted hearts using histology and CFs-specific RNA sequencing to highlight the underlying differences leading to the observed cardiac function.
Abstract P1021: Estimating Cardiac Cell Composition In Gtex With Single-nucleus Reference Profiles.
Authors: Brian Gural, Christoph Rau
Journal: Circulation Research (2023)

Heart failure (HF) is a heterogeneous condition defined by an inability of the heart to meet the circulatory needs of the body. HF is the result of a maladaptive response to chronic stressors during which the heart undergoes structural and cellular remodeling. For example, cardiomyocytes undergo apoptosis after chronic overstimulation while fibroblasts proliferate to fill gaps left by the loss of larger cells. Although changes to the cellular makeup of the heart are known to mediate HF pathology, estimates of basal cardiac cellular composition vary widely. Moreover, despite our understanding of HF as a complex condition that is influenced by environmental and genetic factors, most studies on heart composition only examine small groups of individuals or inbred models. Recent efforts have used single-nucleus RNAseq (snRNAseq) to tally nuclear proportions as a proxy for cellular proportions. However, cellular dissociation biases for certain cell types and skews the resulting estimates. Furthermore, snRNAseq studies are expensive, making them infeasible and underpowered for population-scale analyses. To avoid these issues, we developed a method to estimate cellular composition of bulk RNAseq using cell-type-specific references defined in snRNAseq. While most deconvolution tools are designed for single-cell RNAseq inputs, our method considers the technical and biological differences of snRNAseq. It also allows for the inclusion of additional reference datasets, utilizes simulated controls, and leverages an existing deconvolution tool, MuSiC. We apply our method to the Genome-Tissue-Expression project (GTEx), a multi-tissue database with bulk RNAseq from hundreds of subjects and snRNAseq from a small subset of those subjects. We estimated left ventricular cellular composition in 386 individuals, revealing considerable heterogeneity. We found significant correlations between subject phenotypes and discrete cell populations. This analysis demonstrates our ability to leverage existing, public datasets to accurately map the understudied variability of cardiac cell type variation across human populations. We now look to incorporate genomic datasets to find genetic markers that link composition estimates to population-level variation.
Abstract P1031: An Optogenetic Approach To Study Atrial-fibrillation-associated Remodelling In Atrial Engineered Human Myocardium
Authors: Fiona Popp, Tony Rubio, Fitzwilliam Seibertz, Aiste Liutkute, Tobias Bruegmann, Wolfram H Zimmermann, Runzhu Shi, Nuria Diaz, Niels Voigt
Journal: Circulation Research (2023)

Background: Atrial fibrillation (AF) is the most common clinically reported arrhythmia. It is associated with electrophysiological and structural alterations that promote the maintenance of the disease. The limited longevity of human cardiac samples has historically restricted mechanistic investigation into these remodeling processes of human atrial cardiomyocytes and has hampered antiarrhythmic-therapy development. Objective: We aim to assess if classical AF-associated remodeling events can be elicited in atrial engineered human myocardium (EHM) constructed from atrial subtype-specific induced pluripotent stem cell derived cardiomyocytes (iPSC-CM). Methods: To allow for long-term optical tachypacing at 3 Hz (TP), EHM were generated from cells expressing the light-gated ion-channel f-Chrimson (CRISPR-Cas9 technique). 24-hour or 7 day TP was applied to EHMs. Action potentials (AP) were acquired using the sharp microelectrode impaling technique. Results: 24-hour TP of atrial EHMs resulted in action potential shortening (APD 90 : 215.7±4.9 vs. 243.7±7.3, P &lt;0.01) compared to EHMs paced at 1 Hz. In addition, TP attenuated the response to the M-receptor agonist carbachol. Resting membrane potential was unaffected. In order to more closely simulate persistent AF (clinically diagnosed after 7 consecutive days of AF events), 7 day TP was applied to the EHMs. Similar to 24 hour TP, this produced AP shortening and a blunted response to M-receptor agonists. Interestingly, this also led to hyperpolarization of the resting membrane potential (RMP: -75.1±0.8 vs. -72.5±0.8, P &lt;0.05) compared to EHMs paced at 1 Hz. Conclusion: Classical characteristics of AF-associated remodeling were elicited through TP of EHM. This unique optogenetic technique represents the first in vitro model to investigate the time-dependence of cellular AF-associated remodeling in the long-term. This offers immense potential for drug development studies and personalized approaches for antiarrhythmic therapy.
Abstract P1104: Mantarray 3D Engineered Muscle Tissue Platform Demonstrates Clinically-relevant Disease Stratification Of An <i>In Vitro</i> Human Duchenne Muscular Dystrophy Model
Authors: Shawn Luttrell, Jesse Macadangdang, Kevin Gray, Samir Kharoufeh, Christal Worthen, Greg Luerman, Nicholas Geisse
Journal: Circulation Research (2023)

Accurately modeling disease in vitro is vital for the development of new treatment strategies and therapeutics. For cardiac diseases, direct assessment of contractile output is the “ultimate phenotype” and a reliable metric to study overall tissue function, as other ‘proxy’ measurements or biomarkers are not good predictors of muscle strength. Human 3D engineered heart tissues (EHTs) from induced pluripotent stem cells hold great potential for modeling contractile function. However, the bioengineering strategies required to generate these predictive models present limitations for many investigators. Here, we have developed an instrument platform that utilizes 3D EHTs in conjunction with a label-free, magnetic sensing array (Mantarray). The platform enables facile and reproducible fabrication of 3D EHTs using virtually any cell source and is coupled with parallel direct measurement of contractility. This approach enables clinically relevant functional measurements of muscle, stratification of healthy vs. diseased muscle phenotypes, and facilitates therapeutic modality-agnostic compound safety and efficacy screening. We present a 3D model of Duchenne muscular dystrophy (DMD) that utilizes EHTs formed from an isogenic pair of healthy and diseased cells. DMD tissues display functional deficits across numerous metrics of contractility, including force and relaxation kinetics, though beat rate remains unchanged. EHTs remain functional over months in culture and provide a large experimental window to not only study therapeutic effect, but also disease phenotypes that may present at later stages of development and maturity. We show both acute and chronic effects of compounds in EHTs, including a drug (BMS-986094) that failed clinical trials due to unanticipated cardiotoxicity. These data demonstrate a first-and-only commercial platform that integrates individual, well-based control of electrical stimulation across a 24-well plate of tissues to pace muscle constructs, model force-frequency, and enable exercise regimens or damage protocols. Stimulation is coupled with automated assessment of muscle contraction, providing an inclusive, medium-throughput platform for disease modeling and therapeutic discovery.
Abstract P2142: Evaluation Of Novel A3 Adenosine Receptor Agonist In Hypertension
Authors: Gisele Zapata-Sudo, Bruna Rocha, Jaqueline S Da Silva, Tadeu Montagnoli, Julia G Pedreira, Eliezer J Barreiro
Journal: Circulation Research (2023)

The search for alternative strategies for treatment of cardiovascular diseases, lead to the design and synthesis of N -acylhydrazone derivative, named LASSBio-2062, which is a new ligand of adenosine receptor and that is a possible therapeutic target to reduce blood pressure because of its vasodilatory action and antioxidant properties. This work investigated the effects of a new A 3 adenosine receptor agonist (LASSBio-2062) in spontaneously hypertensive rats (SHR). Animal Care and Use Committee at Universidade Federal do Rio de Janeiro approved the protocols (017/19). Vascular reactivity was evaluated using isometric tension recording of pre-contracted thoracic aorta from male Wistar rats after exposure to increasing concentrations of LASSBio-2062 (0.1 - 100 μM) in the absence or presence of antagonist of adenosine A 2A receptor, ZM-241385 (0.1 μM), an antagonist of adenosine A 3 receptor, MRE 3008F20 (0.1 μM), a blocker of K ATP channel, glibenclamide (10 μM), an inhibitor of Kv channels, 4-AP, inhibitor of BK Ca , TEA (3 mM). Mechanical removal of endothelium increased the EC 50 for vasodilation from 15.5 ± 6.5 to 49.4 ± 10.0 μM, indicating partial dependence on the functional integrity of vascular endothelium. Vascular relaxation was not altered by ZM-241385 but the concentration-response curve shifted to the right with MRE 3008F20 and reduced maximum relaxation from 72.1 ± 4.0 to 23.6 ± 7.7%, indicating that vasodilation occurred by activation of the adenosine receptor type A 3 , but not A 2A . Reduced maximum vascular response by glibenclamide, TEA and 4-AP suggests that activation of A 3 adenosine receptor promotes hyperpolarization as a result reduces intracellular calcium. Antihypertensive effect was investigated in spontaneously hypertensive rats (SHR, 12-15 wks old), through the measurement of mean blood pressure (MBP) after intravenous injection of 10 and 30 μmol/kg of LASSBio-2062. After intravenous administration of LASSBio-2062 (10 umol/kg) in SHR, systolic and diastolic pressures reduced from 155.1 ± 10.1 to 110.6 ± 8.0 and from 111.0 ± 9.1 to 63.9 ± 14.7 mmHg, respectively. HR was also changed from 248.1 ± 12.1 to 146.5 ± 21.0 bpm. In conclusion, the N -acylhydrazone, LASSBio-2062 is a potential therapeutic agent to treat arterial hypertension.
Abstract P1108: Development Of A Vascularized Cardiac Patch Using 3D Bioprinting To Regenerate Injured Myocardium
Authors: Boeun Hwang, Lauren Korsnick, Ming Shen, Holly Bauser Heaton, Vahid Serpooshan
Journal: Circulation Research (2023)

Introduction: Regeneration of the myocardium after ischemic injuries has remained a challenge due to the low proliferative capacity of cardiomyocytes (CMs). With the advance of tissue engineering, various cardiac patch devices have been developed and shown to improve cardiac tissue structure/function after myocardial infarction (MI). However, the therapeutic outcomes of patch devices have been limited by the lack of biological and structural complexity. Leveraging 3D bioprinting and stem cell technologies, this study presents the development of a next generation cardiac patch, integrated with heterogenous multi-cellular architecture, perfusable vasculature, and pro-proliferative molecules. Methods: A hybrid functional bioink, consisting of gelatin methacrylate (GelMA), gelatin, and fibrin, was optimized to fabricate the patch constructs. Two small molecule-based CM expansion techniques were employed, utilizing follistatin-like protein 1 (FSTL1) and CHIR99021 (CHIR), to further enhance the regenerative capacity of the patch. Complex vascular geometries were created by bioprinting sacrificial pluronic bioink in between two cellular composite bioink layers, containing human induced pluripotent stem cell-derived CMs (hiPSC-CMs) and endothelial cells (ECs). The sacrificial ink was subsequently removed to create vascular channels, which were then endothelialized with ECs. Results: Bioprinted patches were successfully cultured under static and dynamic (physiologic flow) culture in vitro . The hiPSC-CMs encapsulated in gelMA-gelatin-fibrin bioink showed adequate long-term viability and function within the 3D environment. The printed vascular channels formed rather uniform endothelium. Both the FSTL1 and CHIR treatments resulted in significant in-situ expansion of hiPSC-CMs within bioprinted cardiac constructs. Further, testing the engineered patch in a rat MI model demonstrated the significant cardioprotective effect of patch. Conclusion: Together, this study introduces a new generation of bioprinted myocardial tissue analogues as a robust research-enabling platform for in vitro testing, and as a novel patch device with markedly enhanced regenerative capacity to treat diseased/damaged adult mammalian heart.
Abstract P3128: Synapse-associated Protein 97 Is Necessary For Enhancing Cardiac Contractility Via Beta1 Adrenoceptor-neuronal Nitric Oxide Synthase Pathway And Guanosine3',5'-cyclic Monophosphate Signaling
Authors: Sherif M Bahriz, Bing Xu, Chaoqun Zhu, Meimi Zhao, Victoria Salemme, Yang K Xiang
Journal: Circulation Research (2023)

Objective: Synapse-associated protein 97 (SAP97) is a scaffold protein widely expressed in the brain, heart, and kidney. SAP97 has been suggested function in the regulation of cardiac contractility. SAP97 directly binds to cardiac beta1 adrenceptor. Our recent studies have shown that increased cAMP and cGMP levels are involved in enhancing excitation-contraction (E-C) coupling after sympathetic nervous system activation. We aim to study the role of SAP97 in beta1 adrenoceptor-induced increases in cyclic nucleotides and cardiac E-C coupling. Results and Methods: Cardiac function in mice with cardiomyocyte-specific deletion of the SAP97 (SAP97-cKO) was comparable to that in flox/flox control littermates. Ligand-induced cGMP signal in freshly isolated adult ventricular myocytes (AVMs) using FRET biosensor Gi500. The cGMP responsiveness caused by β1AR agonist as dobutamine was reduced in SAP97-cKO versus f/f cells. No significant difference between the groups using nonselective beta-adrenergic stimulation isoproterenol (ISO). In comparison, the dobutamine-induced cAMP levels were not reduced in SAP97-cKO when compared to f/f controls. The dobutamine-induced ejection fraction in hearts and sarcomere shortening in AVMs were significantly attenuated in SAP97-cKO hearts and AVMs when compared to f/f controls, respectively. On the other hand, no difference was observed between f/f and cKO AVMs and hearts after stimulation by ISO. To further examine the LTCC activity, whole-cell currents (ICa) were recorded from freshly isolated AVMs. The results showed that the LTCC current was attenuated in SAP97-cKO AVMs than cKO controls when exposed to dobutamine. These results show SAP97 is necessary for increasing intracellular cGMP level, LTCC current, and cardiac E-C coupling and contractility after β1AR stimulation. Conclusion: SAP97 plays a crucial role in β 1 AR signaling, which is necessary for triggering E-C coupling through cAMP and cGMP pathways.